A Call Data Record (“CDR”, also known as Call Detail Record) is a data record which is generated at a telecommunication provider and is related to setup and termination of a call performed by a user through a mobile device and/or any form of data update performed by the mobile device. The CDR can adopt different formats depending on different telecom providers, and can record location information of the mobile device (and of the user who holds the mobile device) and time information of the call. For example, the CDR can include information indicating an initiator of the call (e.g., an ID of the mobile device), information indicating a cell where the initiator initiates the call (e.g., an ID of the cell), information indicating a time at which the initiator initiates the call, information indicating a receiver of the call (e.g., an ID of a mobile device), information indicating a cell where the receiver is located (e.g., an ID of the cell), and a duration of the call. In many applications such as Smarter City, the CDR has become an important data source to predict traffic state changes of the city and the like, through analysis of which the location of the mobile device or the user and a changing trend thereof can be determined.
However, if the location of the mobile device is determined based on the CDR alone, only the cell where the mobile device is located can be determined. The coverage of the cell is relatively large, the location of the mobile device is determined with a low accuracy. Due to changes in wireless signal strength, when the mobile device is located at an edge of the cell, it can be handed over between the cell and an adjacent cell repeatedly. In this case, the accuracy is low because the location of the mobile device is determined based on an uncertain CDR.